This may have been caused by a recently-reported router update. This has primarily been reported with routers supplied by internet providers (Comcast/xFinity, Cox, and AT&T so far), but it's possible they could also occur with other internet providers or user-owned routers that have received updates.
ROKU LOCATES NETWORK AND REPORTS NETWORK QUALITY BUT CANNOT CONNECT Some router updates have changed the router's connection settings in the 2.4 GHz wifi band from b/g/n to just g/n, causing some Rokus connecting to the 2.4 GHz wifi band to lose their ability to connect to the network. The solution is to set the router's 2.4 GHz configuration back to using b/g/n.
If you need to make configuration changes on equipment supplied by your internet provider but you have no access to its settings, you may need to request your internet provider to make the changes for you.
If your problem was not caused the above, often a restart of the router (even if other devices are still connecting) followed by a restart of the Roku may allow the connection to be established. Depending on your Roku model and Roku version number you'll find the System restart option under either Settings > System or Settings > System > Power, or if more convenient you can just unplug the Roku from its power source for a few seconds and let it restart.
Note that for a Roku TV (i.e. one with Roku capability built in) that has "Fast start" enabled, turning the tv off then on does not give a complete restart. Unplug it from its power source for a few seconds or use the menu path indicated above.
Roku Community Streaming Expert I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well. If this post solves your problem please help others find this answer by clicking "Accept as Solution.".
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